The "8.1% annual average" attached to the 20-year bond's 161.8% maturity return is that total divided by 20. The real compound rate is 4.93%, and 4.41% after tax. Coupon and spread, back-calculated by maturity.
A Korean ISA taxes only the net gain after summing every gain and loss inside the account — 2 million won tax-free, 9.9% above that. Run the same trades through a regular brokerage account and the losses vanish from the calculation.
The income deduction on Korea's citizen-participation National Growth Fund is tiered by investment amount — 40%, 20%, then 10% — so it maxes out at 18 million won once you contribute 70 million. Everything above that buys only the 9.9% dividend tax rate.
Dividends from public Korean REITs can be taxed at 9.9% instead of 15.4%. The cap applies to 50 million won of principal, only dividends paid within three years qualify, and you must file with your broker — no retroactive relief.
Korea's individual investor treasury bonds pay their premium, compounding and tax carve-out only at maturity. Using February's rates, here is what 10 million won returns after tax across 5-, 10- and 20-year tranches.
From January 1, 2026, cash dividends from Korean listed firms with a payout ratio of 40% or more can be taxed separately at 14–30% instead of being rolled into comprehensive income. The break-even sits near a 50 million won taxable base.
Domestic dividends start with 15.4% withholding; above 20 million won they roll into comprehensive taxation. From 2026, high-dividend companies add a third track at 15.4–33%. Rate tables and examples break down all three paths.